Integrated cooling system for eco-friendly vehicle

ABSTRACT

The present invention makes it possible to integrate and control in one circuit the systems, such as electric power components, a driving motor, a stack, and an AC condenser which have the maximum enthalpy under similar operational temperature and use conditions, by using an integrated radiator. Therefore, it is possible to minimize air-through resistance of the radiator for cooling the stack and the electric power components and ensure smooth and stable cooling performance of the stack, electric power components, and AC condenser while improving fuel efficiency by reducing the condensation pressure of the air conditioner. Further, it is possible to improve cooling efficiency by non-repeatedly arranging heat exchangers, and reduce the weight of a vehicle, volume of the parts, and the manufacturing cost, by avoiding using too many parts, such as a radiator, a water pump, and a reservoir tank.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a Divisional of U.S. patent application Ser.No. 12/957,078filed Nov. 30, 2010, which claims priority to KoreanPatent Application Numbers 10-2009-0119135 and 10-2010-0117150 filedDec. 3, 2009 and Nov. 23, 2010, respectively, the entire contents ofwhich are incorporated herein for all purposes by these references.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a cooling system for an eco-friendlyvehicle, and more particularly, to a cooling system that cools a stack,electric power components, motors, and an air conditioner coolant in afuel cell vehicle, or cools electric power components, motors, and anair conditioner coolant of a hybrid vehicle or an electric vehicle.

Description of Related Art

Fuel cells have the advantage of generating electricity withoutenvironmental pollution, because they produce little air pollutants andcarbon dioxide, and also have higher electricity generation efficiencythan thermal power generation of the related art, such that eco-friendlyvehicles using a fuel cell as the power source have been increasinglydeveloped.

Meanwhile, hybrid vehicles can appropriately use power from a motor andan engine to drive the vehicles in accordance with traveling conditionsof the vehicles, and the technology of driving a vehicle with a motor isnecessary for the fuel cell vehicles.

It is a problem in driving a vehicle with a motor to dissipate heatgenerated by the operation of the motor and heat generated by phasechange of current in an inverter.

Therefore, it is technologically necessary to cool electric powercomponents, such as the motor and the inverter, and effectively cool thestack of the fuel cell, in fuel cell vehicles.

FIG. 1 is a diagram illustrating a cooling system of a fuel cell vehiclein the related art, which includes a cooling circuit composed ofseparate water pump, reservoir tank, and radiator for cooling electricpower components and a cooling circuit composed of separate water pump,reservoir tank, and radiator for cooing a stack, in which an air-coolingtype AC condenser is disposed between the radiators to cool an airconditioner with a cooling fan.

Further, the cooling system shown in FIG. 2 is a water-cooling type thatcools the AC condenser with water, in which a separate cooling circuitcomposed of a water pump circulating cooling water to the water-coolingtype air conditioner, a reservoir tank, and a radiator for cooling an ACcoolant is included and the radiator for cooling an AC coolant isdisposed between the stack-radiator and the electric powercomponents-radiator to cool them with a cooling fan.

In the cooling systems in the related art, the configuration shown inFIG. 1 has difficulty in ensuring sufficient cooling performance,because the air-cooling type AC condenser increases ventilationresistance for the electric power components-radiator and thestack-radiator. In particular, the electric power components and thestack are operated at low temperature as compared with the existinginternal combustion engines and require a high-capacity radiator becausethe enthalpy is very larger than the internal combustion engines, butthe increase of thickness of the radiator increases ventilationresistance and decreases the amount of heat dissipation, such that atechnology of arranging a cooling module and optimizing the capacity,considering the operational temperature of the electric power componentsand the stack is required.

On the other hand, the configuration shown in FIG. 2 has a problem thatit needs too many parts, such as a radiator, a water pump, and areservoir, by forming cooling circuits for the stack, electric powercomponents, and the AC condenser, decreases the cooling effect byrepeatedly arranging heat exchangers, and has an adverse effect onweight, arrangement of parts, and manufacturing cost of a vehicle.

The information disclosed in this Background of the Invention section isonly for enhancement of understanding of the general background of theinvention and should not be taken as an acknowledgement or any form ofsuggestion that this information forms the prior art already known to aperson skilled in the art.

BRIEF SUMMARY OF THE INVENTION

The present invention has been made in an effort to provide a coolingsystem for an eco-friendly vehicle that minimizes ventilation resistanceof radiators for cooling a stack and electric power components, ensuressmooth and stable cooling performance for the stack, the electric powercomponents, and an AC condenser, improves fuel efficiency by reducingcondensation pressure of the air conditioner, improves coolingefficiency due to non-repeated arrangement of heat exchangers andreduces weight of the vehicle, volume of the parts, and manufacturingcost, without using unnecessarily a number of parts, such as a radiator,a water pump and a reservoir tank.

An exemplary embodiment of the present invention provides an integratedcooling system for an eco-friendly vehicle, which includes: a firstradiator; electric power components disposed to be cooled in a closedcircular cooling circuit including the first radiator; and an ACcondenser disposed to be cooled in the a closed circular cooling circuitincluding the first radiator.

Further, another exemplary embodiment of the present invention providesan integrated cooling system for an eco-friendly vehicle, whichincludes: a second radiator; a stack disposed to be cooled in a closedcircular cooling circuit including the second radiator; and an ACcondenser disposed to be cooled in the a closed circular cooling circuitincluding the second radiator.

According to exemplary embodiments of the present invention, it ispossible to minimize ventilation resistance of radiators for cooling astack and electric power components, ensure smooth and stable coolingperformance for the stack, the electric power components, and an ACcondenser, improve fuel efficiency by reducing the condensation pressureof the air conditioner, and improve cooling efficiency due tonon-repeated arrangement of heat exchangers and reduce weight of thevehicle, volume of the parts, and manufacturing cost, without usingunnecessarily a number of parts, such as a radiator, a water pump, and areservoir tank.

The methods and apparatuses of the present invention have other featuresand advantages which will be apparent from or are set forth in moredetail in the accompanying drawings, which are incorporated herein, andthe following Detailed Description of the Invention, which togetherserve to explain certain principles of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 and FIG. 2 are diagrams illustrating a cooling system of a fuelcell vehicle of the related art.

FIG. 3 is a diagram illustrating a first exemplary embodiment accordingto the present invention.

FIG. 4 is a diagram illustrating a second exemplary embodiment accordingto the present invention.

FIG. 5 is a diagram illustrating a third exemplary embodiment accordingto the present invention.

FIG. 6 is a diagram illustrating a fourth exemplary embodiment accordingto the present invention.

It should be understood that the appended drawings are not necessarilyto scale, presenting a somewhat simplified representation of variousfeatures illustrative of the basic principles of the invention. Thespecific design features of the present invention as disclosed herein,including, for example, specific dimensions, orientations, locations,and shapes will be determined in part by the particular intendedapplication and use environment.

In the figures, reference numbers refer to the same or equivalent partsof the present invention throughout the several figures of the drawing.

DETAILED DESCRIPTION OF THE INVENTION

Reference will now be made in detail to various embodiments of thepresent invention(s), examples of which are illustrated in theaccompanying drawings and described below. While the invention(s) willbe described in conjunction with exemplary embodiments, it will beunderstood that present description is not intended to limit theinvention(s) to those exemplary embodiments. On the contrary, theinvention(s) is/are intended to cover not only the exemplaryembodiments, but also various alternatives, modifications, equivalentsand other embodiments, which may be included within the spirit and scopeof the invention as defined by the appended claims.

Referring to FIGS. 3 to 6, integrated cooling systems for aneco-friendly vehicle according to exemplary embodiments of the presentinvention include: a first radiator 1; a first cooling line 7implementing a closed circular cooling circuit with first radiator 1 andcooling a first part 3 including some of a plurality of electric powercomponents, and a driving motor 5; a second cooling line 11 implementinga closed circular cooling circuit with first radiator 1, in parallelwith first cooling line 7, and cooling a second part 9 including theothers of the electric power components; a second radiator 13; and athird cooling line 17 implementing a closed circular cooling circuitwith second radiator 13 and cooling a stack 15.

That is, first cooling line 7 and second cooling line 11 are arranged inparallel to share first radiator 1, while third cooling line 17implements the closed circular cooling line by individually using secondradiator 13.

In this configuration, third cooling line 17 may be removed in hybridvehicles or electric vehicles which do not use a stack.

Driving motor 5 is a part that supplies driving force for a vehicle andthe electric power components are a plurality of electric components,such as an inverter that handles electricity flowing into/out of drivingmotor 5 by electrically connecting stack 15 with driving motor 5, andsome of the electric components is first part 3 and the other is secondpart 9.

Obviously, the electric power components may be configured to be cooledtogether in first part 3 or may be configured to be cooled together insecond part 9, not divided into first part 3 and second part 9. Further,the electric power components may be disposed to be cooled by all of orany one of first cooling line 7 and second cooling line 11, whichimplement the closed circular cooling circuits including first radiator1.

For reference, the exemplary embodiments shown in FIGS. 3 to 6 exemplifywhen the electric power components are divided into first part 3 andsecond part 9 and arranged to be cooled by both first cooling line 7 andsecond cooling line 11.

First radiator 1 and second radiator 13 are arranged adjacent to eachother in series in the cooling wind path formed by the same cooling fan19.

That is, second radiator 13 is disposed close to cooling fan 19, whilefirst radiator 1 is disposed further from cooling fan 19 than secondradiator 13, such that air sucked by cooling fan 19 passes throughsecond radiator 13, through first radiator 1.

A first pump 23 is disposed between first radiator 1 and a node 21 offirst cooling line 7 and second cooling line 11 to send a coolant fromfirst radiator 1 to node 21 under pressure while a second pump 25 isdisposed between second radiator 13 and stack 15 to send a coolant fromsecond radiator 13 to stack 15 under pressure.

Therefore, first pump 23 pumps up the coolant from first radiator tonode 21, such that some of the pumped coolant circulates to firstradiator 1 along first cooling line 7 from node 21, while the othercirculates to first radiator 1 along second cooling line 11 from node21. Further, the coolant in second radiator 13 is pumped up by a secondpump 25, individually from first cooling line 7 or second cooling line11, and circulates to second radiator 13 through stack 15.

First part 3 and driving motor 5 are arranged in series such that thecoolant that has cooled first part 3 cools driving motor 5 in firstcooling line 7. A first reservoir tank 27 is disposed before first part3 in first cooling line 7 and a second reservoir tank 29 is disposedafter stack 15 in third cooling line 17.

In this configuration, the reason that driving motor 5 is disposed afterfirst part 3 is because the operational temperature of driving motor 5is relatively higher than operational temperature of the electric powercomponents of first part 3, and this is for allowing the coolant coolsdriving motor 5 after cooling first part 3.

The configuration described above is in common in the first exemplaryembodiment to the fourth exemplary embodiment and the exemplaryembodiments have a difference in the position of AC condensers disposedin the common configuration.

In the first exemplary embodiment of FIG. 3 an AC condenser 31 isdisposed after second part 9 of second cooling line 11 to be cooled bythe coolant that has cooled second part 9.

Obviously, the operational temperature of the electric power componentsdepends on the types, such that the electric power components may bedisposed after AC condenser 31 in some cases.

That is, the electric power components of second part 9 and AC condenser31 are arranged in series in second cooling line 11, the same coolingcircuit, while AC condenser 31 can be considered to be arranged inparallel with respect to first part 3 and the driving motor in firstcooling line 7.

Obviously, AC condenser 31 is included in a cooling circuit including anevaporator 33, a compressor, an expansion valve 41, and a receiver 35 tocool the interior of a vehicle.

In this configuration, it is preferable that the compressor is anelectric compressor 37 such that the operation can be controlled on thebasis of the operational states of the devices in the cooling lineincluding AC condenser 31, for example, driving motor 5, first part 3,second part 9, or stack 15, depending on the exemplary embodiments.

That is, in the first exemplary embodiment of FIG. 3, second part 9 iscooled by second cooling line 11 that is the same cooling line of ACcondenser 31, in which it is possible to improve fuel efficiency of thevehicle and performance of cooling the interior due to reduction ofcondensation pressure of the AC coolant by increasing the coolingperformance of AC condenser 31 by using first radiator 1 under smalloutput of second part 9, whereas it is possible to improve coolingperformance of second part 9 by reducing the output of electriccompressor 37 such that the amount of heat discharged from AC condenser31 is reduced, under large output of second part 9.

In the second exemplary embodiment of FIG. 4, an AC condenser 31 isdisposed between first part 3 and driving motor 5 in first cooling line7 to be cooled by the coolant that has cooled first part 3.

In this configuration, AC condenser 31 may be considered to be arrangedin series in the same cooling line with respect to first part 3 and maybe considered to be connected in parallel to first radiator 1 withrespect to second part 9, in which first part 3 and second part 9 maynot be necessarily divided, as shown in FIG. 4, and may be collected atany one of them to be cooled together.

In this exemplary embodiment, AC condenser 31 is disposed to be cooledtogether with first part 3 and driving motor 5 by the coolant flowingalong first cooling line 7 and first cooling line 7 is configured suchthat AC condenser 31 is cooled by the coolant passing through first part3 having lower operational temperature than AC condenser 31 and drivingmotor 5 having higher operational temperature than AC condenser 31 isthen cooled by the coolant that has cooled AC condenser 31.

Similarly, in this exemplary embodiment, it is possible to improve fuelefficiency of a vehicle and cooling performance due to reduction ofcondensation pressure of the AC coolant by increasing the coolingperformance of AC condenser 31, using electric compressor 37 included inthe same cooling circuit of AC condenser 31, when the output of firstpart 3 and driving motor 5 is low, and it is possible to improveperformance of cooling first part 3 and driving motor 5 by reducing theoutput of electric compressor 37, when the output of first part 3 anddriving motor 5 is large, thereby improving the commercial value of thevehicle.

In the third exemplary embodiment of FIG. 5, an AC condenser 31 isarranged in parallel with a stack 15 with respect to a second pump 25and a second radiator 13 to be cooled with stack 15 by a coolant fromsecond pump 25 of third cooling line 17.

Further, a third pump 39 is further disposed between first reservoirtank 27 and first part 3 in first cooling line 7.

That is, as second pump 25 pumps up a coolant from second radiator 13and supplies the coolant simultaneously to AC condenser 31 and stack 15,AC condenser 31 and stack 15 are separately cooled and the coolantreturns to second radiator 13, while third pump 39 in first cooling line7 strengthens the flow of the coolant flowing along first cooling line 7such that the cooling performance of first part 3 and driving motor 5 ismore improved than second part 9.

Similarly, in this exemplary embodiment, it is possible to improve fuelefficiency of a vehicle and performance of cooling the interior due toreduction of condensation pressure of the AC coolant by increasing thecooling performance of AC condenser 31, using second radiator 13, undersmall output of stack 15, while it is possible to improve the coolingperformance of stack 15 by decreasing the output of electric compressor37 such that the amount of heat discharged from Ac condenser 31 isreduced, under large output of stack 15.

FIG. 6 is a diagram showing the fourth exemplary embodiment of thepresent invention, in which an AC condenser 31 is disposed between asecond pump 25 and stack 15 in third cooling line 17 to be cooled by acoolant from second pump 25, and a third pump 39 is disposed betweenfirst reservoir tank 27 and first part 3 in first cooling line 7.

AC condenser 31 and stack 15 are arranged to be cooled in series inthird cooling line 17, in which stack 15 is cooled by the coolant thathas cooled AC condenser 31 because the operational temperature of the ACcondenser is lower than the operational temperature of stack 15.

In this configuration, the condensation temperature of the coolant ofthe cooling circuit including the AC condenser depends on the types,such that the stack may be disposed before the AC condenser in somecases. That is, it is preferable that the AC condenser is disposed afterthe stack, when the coolant is carbon dioxide (CO₂).

Similarly, in this exemplary embodiment, it is possible to improve fuelefficiency of a vehicle and performance of cooling the interior due toreduction of condensation pressure of the AC coolant by increasing thecooling performance of AC condenser 31, using second radiator 13, undersmall output of stack 15, while it is possible to improve the coolingperformance of stack 15 by decreasing the output of electric compressor37 such that the amount of heat discharged from Ac condenser 31 isreduced, under large output of stack 15.

According to exemplary embodiments of the present invention describedabove, it is possible to reduce the number of pump, reservoir tank, andradiator, decrease the weight of a vehicle, ensure a space for an engineroom, as compared with when a cooling circuit for electric powercomponents and a cooling circuit for AC condenser 31 are separatelyprovided in the related art, and consequently, it is possible to reducethe manufacturing cost of a vehicle.

Further, first radiators 1 cooling AC condensers 31 of the firstexemplary embodiment and the second exemplary embodiment can improvecooling efficiency by increasing capacity more than the radiator forelectric power components of the related art such that flow resistanceof the coolant therein reduces and the flow rate of the coolantcorrespondingly increases. Further, second radiator 13 of the thirdexemplary embodiment and the fourth exemplary embodiment can improvecooling efficiency by increasing capacity more than the stack-radiator15 of the related art such that flow resistance of the coolant thereinreduces and the flow rate of the coolant correspondingly increases.

Further, according to the radiators in the first exemplary embodiment tothe fourth exemplary embodiment, as described above, since only tworadiators, first radiator 1 and second radiator 2, overlap each other,air-through resistance is reduced as compared with when three or moreradiators overlap each other in the related art, such that it ispossible to achieve improved cooling efficiency.

As described above, the present invention makes it possible to integrateand control in one circuit the systems, such as electric powercomponents, a driving motor, a stack, and an AC condenser which have themaximum enthalpy under similar operational temperature and useconditions, by using an integrated radiator. Therefore, it is possibleto minimize air-through resistance of the radiator for cooling the stackand the electric power components and ensure smooth and stable coolingperformance of the stack, electric power components, and AC condenserwhile improving fuel efficiency by reducing the condensation pressure ofthe air conditioner. Further, it is possible to improve coolingefficiency by non-repeatedly arranging heat exchangers, and reduce theweight of a vehicle, volume of the parts, and the manufacturing cost, byavoiding using too many parts, such as a radiator, a water pump, and areservoir tank.

The foregoing descriptions of specific exemplary embodiments of thepresent invention have been presented for purposes of illustration anddescription. They are not intended to be exhaustive or to limit theinvention to the precise forms disclosed, and obviously manymodifications and variations are possible in light of the aboveteachings. The exemplary embodiments were chosen and described in orderto explain certain principles of the invention and their practicalapplication, to thereby enable others skilled in the art to make andutilize various exemplary embodiments of the present invention, as wellas various alternatives and modifications thereof. It is intended thatthe scope of the invention be defined by the Claims appended hereto andtheir equivalents.

What is claimed is:
 1. An integrated cooling system for an eco-friendlyvehicle, comprising: a first radiator connected on a first closedcircular cooling circuit with a first pump disposed directly in front ofand branching through a node so as to simultaneously cool electric powercomponents including a first part and a second part and disposed inparallel, and wherein the first part is arranged before a driving motorwhich has higher temperature than that of the first part; a secondradiator, wherein the first radiator and the second radiator arearranged adjacent to each other in series in a cooling wind path formedby the same cooling fan; a stack disposed to be cooled in a secondclosed circular cooling circuit including the second radiator; and an ACcondenser disposed to be cooled in the second closed circular coolingcircuit including the second radiator, wherein the stack and the ACcondenser are arranged in parallel with the second radiator, the ACcondenser is connected to implement a cooling circuit, together with anelectric compressor having variable cooling capacity, and wherein thesecond part is disposed adjacent to the AC condenser, and wherein acooling performance of the AC condenser is configured to be increased byusing the second radiator under a small output of the stack, a coolingperformance of the stack is configured to be improved by decreasing anoutput of the electric compressor such that an amount of heat dischargedfrom an AC coolant of the AC condenser is reduced under a large outputof the stack.
 2. The integrated cooling system for an eco-friendlyvehicle as defined in claim 1, wherein the second radiator is disposedclose to the cooling fan, and the first radiator is disposed furtherfrom the cooling fan than the second radiator, such that air sucked bythe cooling fan passes through the second radiator, through the firstradiator.
 3. The integrated cooling system for an eco-friendly vehicleas defined in claim 1, wherein the driving motor is arranged in seriesin the cooling circuit including the electric power components.
 4. Theintegrated cooling system for an eco-friendly vehicle as defined inclaim 1, wherein the driving motor is arranged in parallel with thefirst radiator and the electric power components are arranged inparallel with the first radiator.
 5. The integrated cooling system foran eco-friendly vehicle as defined in claim 2, wherein the electricpower components are divided into a plurality of parts and each part ofthe electric power components is in parallel with the first radiator,wherein the plurality of parts include the first part and the secondpart.
 6. The integrated cooling system for an eco-friendly vehicle asdefined in claim 2, wherein a pump and a reservoir tank are furtherdisposed in the first cooling circuit connected to the first radiator.7. The integrated cooling system for an eco-friendly vehicle as definedin claim 1, wherein the coolant of the AC condenser is carbon dioxide.